1. Field of the Invention
This invention relates to a container assembly for a food stuff and a cover thereof. Further, this invention relates to the container assembly and the cover suitable for cooking a food stuff therein with a heating device such as a microwave.
2. Description of the Related Art
A container assembly comprising a container for a food stuff and a cover for covering an opening on a top of the container is often used in a daily life, for example, as a container assembly may contain a food stuff and then may be placed in a refrigerator for storage of the food stuff, or may be used as a lunch box.
It is advantageous that such a container assembly is repeatedly used. An exemplary preservation/storage may be to cover a food stuff in a bowl with a resin film and place the bowl in a refrigerator. This exemplary preservations/storage essentially requires waste of the resin film after its usage. On the other hand, the above mentioned container with the cover may not produce any waste.
In general, the cover of the container assembly for the food stuff may hygienically seal the container assembly. When the food stuff in the container assembly is microwaved, the cover has to be removed from the container. This is because an increase in an inner pressure of the container assembly during heating process due to an airtight sealing by the cover attached to the container may blow out the cover or destroy the container.
Japanese Patent No. 3513599 discloses a container assembly useful for solving the above-described inconvenience in use. FIG. 14 is a schematic perspective view of the container assembly disclosed in Japanese Patent No. 3513599. FIG. 15 is a longitudinal cross-sectional view of the container assembly shown in FIG. 14.
A container assembly (C) in FIG. 14 and FIG. 15 includes a container (B) and a cover (L). The container (B) for a food stuff is configured to have a bottom and side walls surrounding the bottom. The cover (L) covers an opening at a top of the container (B).
The cover (L) comprises a central area (M) and a peripheral area (P). The central area (M) and the peripheral area (P) connected each other are molded through a double-molding process.
The central area (M) includes an aperture (0). The peripheral area (P) connects with a flap (F). The flap (F) extends to a center of the cover (L) from the peripheral area (P). The protrusion (S) extending downwardly is formed on a bottom of the flap (F).
The flap (F) rotates upwardly and downwardly with respect to a proximal end (A) connecting with the peripheral area (P). When the flap (F) is in parallel with the top of the cover (L) by its downward rotation, the protrusion (S) engages with and closes the aperture (O) defined in the cover (L).
A container assembly (C) in FIG. 14 and FIG. 15 does not require to remove the cover (L) when heating the food stuff therein, because a the container assembly (C) may be capable of exhausting a water vapor from the food stuff or inflating air therein so as to avoid an excessive inner pressure.
Thus, the container assembly (C) in FIG. 14 and FIG. 15 can overcome the above-described inconvenience when in use.
The container assembly disclosed in Japanese Patent No. 3513599 has a disadvantage of high production cost although it has a superior feature to overcome the conventional inconvenience when in use, because the cover (L) is manufactured through the double-molding process which requires many process steps.
FIG. 16 shows a container assembly (C) which overcomes the expensive production cost caused by the double-molding process.
The container assembly (C) in FIG. 16 is substantially similar to a configuration of the container assembly (C) described relating to FIG. 14 and FIG. 15 except for a joint structure between the flap (F) and the cover (L) by an assembly process.
Thus, the flap (F) and the cover (L) are individually molded through a resin-molding process, and then integrally jointed each other through the assembly process.
The container assembly (C) in FIG. 16 can be manufactured without a complicated process such as the double-molding process. However, the assembly process is still required, therefore reduction in the manufacturing cost may not be enough.
Further, the container assembly (C) in FIG. 16 has another problem. The flap (F) and the cover (L) are originally separate components although they are integrated through the assembly process. During long usage, the flap (F) happens to drop off the cover (L). A reattachable configuration of the flap (F) may somehow overcome the above-described problem, but if the flap (F) is lost after dropping off, the container assembly is no longer reparable.
In order to solve the problems described above, the present invention provides a cover which can be manufactured without any complicated manufacturing processes. The present invention further provides a cover from which a flap does not fall. The present invention also provides a container assembly using the cover described above.